The present invention relates to a data storage device and data storage device control method, and more particularly to a write control technology depending on the detected impact.
Various devices using optical disks, magnetic tapes, and other media are known as data storage devices. Among others, a hard disk drive (HDD) is now widely used as a storage device for use with a computer and counted as an essential storage device for a present-day computer system. Due to its excellent characteristics, the hard disk drive has found an increasingly wide range of applications, including not only a computer but also a motion picture recorder/reader, a car navigation system, a sound recorder/reader, a cellular phone, and a removable memory for use with a digital camera.
The hard disk drive comprises a magnetic disk for storing data, a head element section for performing a data read/write operation in relation to the magnetic disk, a slider to which the head element section is fastened, and an actuator for holding the slider and moving the head element section to a desired position over the magnetic disk. The actuator is driven by a voice coil motor. When turned on a pivot, the actuator radially moves a head over a rotating magnetic disk. This allows the head element section to access a desired track that is formed on the magnetic disk and perform a data read/write process.
Within the hard disk drive, the actuator, which pivots, moves the head element section. Therefore, extraneous impact may vibrate a mechanism to the detriment of data read/write accuracy. Particularly if any impact is applied from the outside during a write sequence, the head element section writes data on a track other than a target track (off-track write) due to actuator movement or vibration, thereby erasing necessary data on the magnetic disk.
Under the above circumstances, the technology disclosed, for instance, by Patent Document 1 (Japanese Patent Laid-Open No. 2002-109840) makes it possible to position a shock sensor so as to measure the X and Y components of impact applied to the disk surface, calculate the radial component of the impact from current position information, which the head element section reads from the disk, and reduce the head positioning error that may be caused by extraneous vibration or impact.